In winter, the weather is very cold. So some people feel sick in the cold weather. If you don't wear warm clothes, you will have a cold. How do you feel if you have a cold? You will be very tired(累的). Your temperature(体温) will be higher than 37 degrees. Then you will have a fever. But don't worry if you are sick. You should go to see a doctor, take some medicine, stay in bed for a few days and drink more hot water.Then you will get better soon.